Boilers



June 18, 1957 BOILERS Filed May 25, 1953 k-Qa J. W. THROCKMORTON ETAL 2 Sheets-Sheet 1 4; INVENTORS 5 A TOW ATTO R N EY June 18, 1957 J. w. THROCKMORTON ETAL 2,795,051

BOILERS 2 Sheets-Sheet 2 Filid May 25, 1955 I INVENTORS JZ /m him/Win01 By .fa/m S Willi/s United States Patent BOILERS John W. Throckmorton and John S. Wallis, New York,

N. Y., assignors to Petra-Chem Process Company, Incorporated, New York, N. Y., a corporation of Delaware Application May 25, 1953, Serial No. 357,124

3 Claims. (Cl. l22322) This invention relates to improvements in boilers and furnaces and pertains more particularly to a cylindrical or multi-sided upright furnace in which the burners are located in the bottom and discharge flames upwardly in an axial direction and in which the combustion gases are discharged through an integral stack or line gas outlet at the top.

The boiler is an improvement upon the structures shown and described in our co-pending application Serial No. 173,301, filed July 12, 1950, now abandoned, and incorporates certain advantages of Throckmorton et al. Patent 2,375,505, issued May 8, 1945, but possesses advantages and economies not found in our previous inventions.

The construction of the invention is particularly well adapted for boilers of immense capacity and may, for example, include a single cylindrical vertical drum 5% ft. in diameter and 30 ft. tall, directly supported from the foundation, and an outer cylindrical furnace shell forming a distinct radiant heating zone composed of an annular furnace chamber where heat is transmitted primarily by radiation, which extends vertically for more than ft. before it begins to taper and discharge into a narrow annular passage, which constitutes a distinct convection zone.

Boiler tubes are arranged in two circular banks, one near the wall of the furnace shell and the other following the contour of and being located close to the inner wall of the furnace, which is constituted by the large central drum, and by a baflie which has a cylindrical section at the convection zone, and a conical section connecting the radiant and convection zones and deflecting the hot gases from the radiant zone into the convection zone.

All of the tubes are connected with and are supported by the large cylindrical drum.

Since the drum is very heavy and is supported directly from the foundation, the large cylindrical furnace shell is relatively light and is independently supported on the foundation and carries only the economizer and the stack in addition to its own weight, as hereinafter set forth.

Accordingly, it is an object of the invention to provide a boiler construction which is peculiarly well adapted for use in very large sizes and enormous capacities and in which the burners are so placed that flames of very high intensity may safely be discharged upwardly in a direction parallel to the axis of the boiler, without impinging upon any of the boiler tubes until a considerable percentage of the heat has been extracted by radiation.

Other objects and advantages will appear from the following description, taken together with the accompanying drawings, in which Fig. l is a sectional elevation of a boiler which constitutes one embodiment of our invention;

Fig. 2 is a sectional view taken along the line 22 of Fig. l; and

Fig. 3 is a sectional view taken along the line 3--3 of Fig. 1.

Referring to the drawings:

A central cylindrical water drum is mounted directly on the furnace foundation 126 by heavy cylindrical plates 127. The water drum is concentrically mounted with a large outer cylindrical furnace shell 128 and a large battle composed of a sleeve 129 and a cone 130 is mounted on the water drum, being supported therefrom by radial supports 131 and 132. The outer furnace shell is supported from the foundation by beams 133 and the furnace floor 134 has a plurality of upshot burners 135 distributed circumferentially as shown in Fig. 2. The boiler is provided with a forced draft fan 136, driven by a steam turbine 1360.

Water tubes 138 are mounted near the Wall of the furnace chamber 128 in a circular bank and another bank of water tubes 139, which are mounted in staggered relation to avoid crowding, as shown in Fig. 2, but constitute a Single bank since every tube can "see the flame from the furnace and is thus exposed to direct radiant heat, follow the contour of the inner wall of the furnace chamber, being close to the drum 125 throughout the main portion of the radiant section of the furnace. This portion may, for example, be 10 ft. tall. They then follow the conical section 130 of the baffle and finally are parallel to the sleeve section 129 of the baffle as they pass through the convection zone. The tubes at each end are connected to the drum. Both banks of tubes 138 and 139 have extended surfaces or fins at the convection section of the heater. The cone occupies approximately the upper third of the radiant zone of the furnace, and the sleeve 129 provides a narrow annulus, although it is of large radius, which tends to increase the velocity of the furnace gases as they pass upwardly through the convection zone in direct contact with the fin section of the tubes.

For convenience the radiant zone of the furnace is designated 141 and the convection zone is designated 140.

The water tubes are connected at the bottom to manifolds 144, of which there are three, but only one of which is shown in Fig. 2 in dotted lines. These are connected to the drum near its lower end by radial tubes 145. Blowdown connections 149 are provided for each of the manifolds 144.

In this particular embodiment of our invention, onefourth of the outer bank of tubes constitute steam superheated tubes and these tubes are connected to a separate manifold 142, which has a superheated steam outlet 143. 148 is a safety valve and 150 are observation ports.

The burners 135 produce very intense flames which extend upwardly, parallel to the axis of the boiler and do not impinge on any of the boiler tubes until they reach the upper portion of the radiant section adjacent to the frusto-conical inner wall of the furnace, formed by the conical section 130 of the battle. The tubes absorb heat with extreme efficiency and in large quantities by radiation and the temperature of the hot gases is considerably reduced when they begin to contact the tubes in the upper portion of the radiant section, and the temperature is still further reduced before the hot gases scrub the fin section of the tubes in the convection zone of the heater.

By this arrangement, it is safe and very economical to use burners which produce extremely hot flames, and the tubes are not subject to overheating.

Modifications and variations of our invention may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A boiler comprising a vertical cylindrical water drum having a constant diameter throughout its length; said drum having an unobstructed interior for substantially the entire height of water column therein; a large cylindrical furnace shell concentrically surrounding said drum and forming an annular combustion chamber therearound; a baflie mounted on the drum near its upper end; said baffle having an upper cylindrical sleeve section only slightly smaller in diameter than the furnace shell and a lower frusto-conical section tapering to the surface of said drum; the vertical dimensions of said bafile relative to said drum being such that a large and relatively tall annular radiant zone of said combustion chamber is formed in the lower half of the furnace, a narrow annular convection zone of said combustion chamber is formed at the upper end of the furnace, and a tapering connecting zone of said combustion chamber is located between the other two zones; a bottom for said annular combustion chamber having a plurality of burners circumferentially distributed and arranged to discharge hot flame and gases axially of the furnace into said combustion chamber; two circular banks of water tubes, one located close to and following the contours of the inner wall of said combustion chamber, and one located close to said furnace shell; both of said banks of tubes having fin sections on the tubes as they pass through said narrow annular convection zone of the chamber; and radial tube sections connecting the water tubes to the drum near its ends.

2. A boiler comprising a vertical cylindrical water drum having a constant diameter throughout its length; said drum having an unobstructed interior for substantially the entire height of water column therein; a large cylindrical furnace shell concentrically surrounding said drum and forming an annular combustion chamber therearound; a baflle mounted on the drum near its upper end; said baflle having an upper cylindrical sleeve section only slightly smaller in diameter than the furnace shell and a lower frusto-conical section tapering to the surface of said drum; the vertical dimensions of said baflle relative to said drum being such that a large and relatively tall annular radiant zone of said combustion chamber is formed in the lower half of the furnace, a narrow annular convection zone of said combustion chamber is formed at the upper end of the furnace, and a tapering connecting zone of said combustion chamber is located between the other two zones; at bottom for said annular combustion chamber having a plurality of burners circumstantial- ]y distributed and arranged to discharge hot flame and gases axially of the furnace into said combustion chamber; two single row circular banks of water tubes, one located close to and following the contours of the inner wall of said combustion chamber, and one located close to said furnace shell; said one bank located close to the inner wall of said chamber having a single row circular configuration in said narrow convection zone, and having a double row configuration by being radially staggered to avoid crowding in said connecting and radiant zones; both of said banks of tubes having fin sections on the tubes as they pass through said narrow annular convection zone of the chamber; and radial tube sections connecting the water tubes to the drum near its ends.

3. A boiler comprising a vertical cylindrical water drum having a constant diameter throughout its length; said drum having an unobstructed interior for substan tially the entire height of water column therein; a large cylindrical furnace shell concentrically surrounding said drum and forming an annular combustion chamber therearound; a battle mounted on the drum near its upper end; said bafiie having an upper cylindrical sleeve section only slightly smaller in diameter than the furnace shell and a lower frusto-conical section tapering to the surface of said drum; the vertical dimensions of said battle relative to said drum being such that a large and relatively tall annular radiant zone of said combustion chamber is formed in the lower half of the furnace, a narrow an nular convection zone of said combustion chamber is formed at the upper end of the furnace, and a tapering connecting zone of said combustion chamber is located between the other two zones; a bottom for said annular combustion chamber having a plurality of burners circumferentially distributed and arranged to discharge hot flame and gases axially of the furnace into said combustion chamber; two circular banks of water tubes, one located close to and following the contours of the inner wall of said combustion chamber, and one located close to said furnace shell; both of said banks of tubes having fin sections on the tubes as they pass through said narrow annular convection zone of the chamber; the tubes in said inner bank being staggered radially in said lower two zones to avoid circumferential crowding; and radial tube sections connecting the water tubes to the drum near its ends.

References Cited in the file of this patent UNITED STATES PATENTS 2,271,880 Wood Feb. 3, 1942 2,375,505 Throckmorton et al May 8, 1945 2,630,104 Harvey Mar. 3, 1953 FOREIGN PATENTS 350,065 France July 19, 1905 

